<?php
class hes3tools{
	public  function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0) {

		$key = $key?$key:Configure::read('HEMS2_COOKIEMI');
		    // 动态密匙长度，相同的明文会生成不同密文就是依靠动态密匙
		    // 加入随机密钥，可以令密文无任何规律，即便是原文和密钥完全相同，加密结果也会每次不同，增大破解难度。
		    // 取值越大，密文变动规律越大，密文变化 = 16 的 $ckey_length 次方
		    // 当此值为 0 时，则不产生随机密钥
		    //$ci = & get_instance();
		//$ci->load->config('common');
		$ckey_length = 4;
		// 密匙
		$key = md5($key);
	    // 密匙a会参与加解密
	    $keya = md5(substr($key, 0, 16));
	    // 密匙b会用来做数据完整性验证
	    $keyb = md5(substr($key, 16, 16));
	    // 密匙c用于变化生成的密文
	    $keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
	    // 参与运算的密匙
	    $cryptkey = $keya.md5($keya.$keyc);
	    $key_length = strlen($cryptkey);
	    // 明文，前10位用来保存时间戳，解密时验证数据有效性，10到26位用来保存$keyb(密匙b)，解密时会通过这个密匙验证数据完整性
	    // 如果是解码的话，会从第$ckey_length位开始，因为密文前$ckey_length位保存 动态密匙，以保证解密正确
	    $string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
	    $string_length = strlen($string);
	    $result = '';
	    $box = range(0, 255);
	    $rndkey = array();
	    // 产生密匙簿
	    for($i = 0; $i <= 255; $i++) {
	        $rndkey[$i] = ord($cryptkey[$i % $key_length]);
	    }
	    // 用固定的算法，打乱密匙簿，增加随机性，好像很复杂，实际上并不会增加密文的强度
	    for($j = $i = 0; $i < 256; $i++) {
	        $j = ($j + $box[$i] + $rndkey[$i]) % 256;
	        $tmp = $box[$i];
	        $box[$i] = $box[$j];
	        $box[$j] = $tmp;
	    }
	    // 核心加解密部分
	    for($a = $j = $i = 0; $i < $string_length; $i++) {
	        $a = ($a + 1) % 256;
	        $j = ($j + $box[$a]) % 256;
	        $tmp = $box[$a];
	        $box[$a] = $box[$j];
	        $box[$j] = $tmp;
	        // 从密匙簿得出密匙进行异或，再转成字符
	        $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
	    }
	    if($operation == 'DECODE') {
	        // 验证数据有效性，请看未加密明文的格式
	        if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
	            return substr($result, 26);
	        } else {
	            return '';
	        }
	    } else {
	        // 把动态密匙保存在密文里，这也是为什么同样的明文，生产不同密文后能解密的原因
	        // 因为加密后的密文可能是一些特殊字符，复制过程可能会丢失，所以用base64编码
	        return $keyc.str_replace('=', '', base64_encode($result));
	    }
	}
	/** 
    * Respose A Http Request 
    * 
    * @param string $url 
    * @param array $post 
    * @param string $method 
    * @param bool $returnHeader 
    * @param string $cookie 
    * @param bool $bysocket 
    * @param string $ip 
    * @param integer $timeout 
    * @param bool $block 
    * @return string Response 
    */  
    function httpRequest($url,$post='',$method='GET',$limit=0,$returnHeader=FALSE,$cookie='',$bysocket=FALSE,$ip='',$timeout=15,$block=TRUE) {  
       $return = '';  
       $matches = parse_url($url);  
  
       !isset($matches['host']) && $matches['host'] = '';  
       !isset($matches['path']) && $matches['path'] = '';  
       !isset($matches['query']) && $matches['query'] = '';  
       !isset($matches['port']) && $matches['port'] = '';  
  
       $host = $matches['host'];  
       $path = $matches['path'] ? $matches['path'].($matches['query'] ? '?'.$matches['query'] : '') : '/';  
       $port = !empty($matches['port']) ? $matches['port'] : 80;  
  
       if(strtolower($method) == 'post') {  
           $post = (is_array($post) and !empty($post)) ? http_build_query($post) : $post;  
           $out = "POST $path HTTP/1.0\r\n";  
           $out .= "Accept: */*\r\n";  
           //$out .= "Referer: $boardurl\r\n";  
           $out .= "Accept-Language: zh-cn\r\n";  
           $out .= "Content-Type: application/x-www-form-urlencoded\r\n";  
           $out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";  
           $out .= "Host: $host\r\n";  
           $out .= 'Content-Length: '.strlen($post)."\r\n";  
           $out .= "Connection: Close\r\n";  
           $out .= "Cache-Control: no-cache\r\n";  
           $out .= "Cookie: $cookie\r\n\r\n";  
           $out .= $post;  
       } else {  
           $out = "GET $path HTTP/1.0\r\n";  
           $out .= "Accept: */*\r\n";  
           //$out .= "Referer: $boardurl\r\n";  
           $out .= "Accept-Language: zh-cn\r\n";  
           $out .= "User-Agent: $_SERVER[HTTP_USER_AGENT]\r\n";  
           $out .= "Host: $host\r\n";  
           $out .= "Connection: Close\r\n";  
           $out .= "Cookie: $cookie\r\n\r\n";  
       }  
  
       $fp = fsockopen(($ip ? $ip : $host), $port, $errno, $errstr, $timeout);  
  
       if(!$fp) return ''; else {  
           $header = $content = '';  
  
           stream_set_blocking($fp, $block);  
           stream_set_timeout($fp, $timeout);  
           fwrite($fp, $out);  
           $status = stream_get_meta_data($fp);  
  
           if(!$status['timed_out']) {//未超时  
               while (!feof($fp)) {  
                   $header .= $h = fgets($fp);  
                   if($h && ($h == "\r\n" ||  $h == "\n")) break;  
               }  
  
               $stop = false;  
               while(!feof($fp) && !$stop) {  
                   $data = fread($fp, ($limit == 0 || $limit > 8192 ? 8192 : $limit));  
                   $content .= $data;  
                   if($limit) {  
                       $limit -= strlen($data);  
                       $stop = $limit <= 0;  
                   }  
               }  
           }  
        fclose($fp);  
  
           return $returnHeader ? array($header,$content) : $content;  
       }  
    }		
}
